hbnet hulskamp



s T HH d A treuren sri l G. HENRY HULSKABIP.

Oli TROY, NEWT YORK.

To @ZZ whom it iii/wy concern.-

Be it known that G. HENRY HUrsirnMeof the city of Troy, in the county of Rensselaer andthe Stateof New York, have invented a new and useful Improvement in the Actions of Piano-Fortes;and i de hereby declare that the following is a full end enact description thereof, referelice-being had to the annexed dran-'ings,and the letters of reference marked thereo Y My 'improvement is represented "by the drawing, which is yertieai section through the middle of one of thevlreys AUA.. ,it represents the several parts in, their full size and proper proportions. rEhe red-shaded parts are those that are covered with cloth or bucks ein to prevent*noise. rlibe blue-shaded perte are screws, metallic wires, Snc.

A bar, B, .extending lengthwise across the pianoforte, is iirmly attached to the frame in the ,usual manner.l Tol this bar is screwed the hinge-butt C, and to the latter is attach-ed thel hanime-butt Divith' the beinA nier Eby the joint l.' Upon the lreysAA, I attach a lever, F, bythe screws G and E, and to thisvlerer is attached the jack er hammer-lifter i-by the' joint 2. To the 'ack or hammer-lifter is attached bv the oint 3 J 9 v i K mayv be readily adjusted.

Aa detachenf- (Represented at J.) This is pressed .upward by a spring, N, inserted into the lei'v-er l?, and bearing rtgainst a projection on the detaeher until the `upward motion of the rietaeher is arrested by s stop, lQattaehed te theprojectien on Si lya se'rew thelengthof To the detacher J` is also attached e stein er screw, L, apen .which a round-heeded polished nut is screwed. It heightv can be adj usted by its serew,in orderY to bear against the Vpoint lli of the hammerbutt D, for the object hereinafter stated. The wire spring N also serves to press the hammer-lifter or jack against the hammer-butt l).v

O is the back check, to prevent the rebound ot the hammer, in the usual form. A wire spring, l?, attached to the hinge-butt C, pressingngainst a piece of felt, Y, glued ontothe side of thcliammer-butt, serves to support and to regulate the weight of the hammer. Alittle cnt is made in the felt-,t0 receive the spring.-

, "ilhe )oints itl. and X ofthe hammer-butt are et the lsaine distance from the center and should betniade to press equally on the ending ef the jack end. the end of the nut on L; but when the hammer is raised by pressing on the key as the point lli moves somewhat backward toward the jack as Well as upward and the unt moves forward and upward, they be come disconnected by a smell space, so that the point lri has a free motion toward the jack, without touching the sai1ie,wl1en the hammer is raised.

represents one ofthe strings.

The operation is as follows: When the back part ef the key is raised by pressing down the front of it, the hammer 'ill be carried rigidly upward by the jack pressing against the hammer-buttnntil it has been brought to Withinl three-eighths of an inch from the strings. Then the end ot" thedetaCherr strikes against the bar B, pushes the jack out from under X, and becomes fully detached when the hammer has been brought to within about Oneeighth Gf an inch from the strings.v After the blow has been given the hammer will descend about I one-'haltet' an inch. The point M will then fall upon the nut on L, the hammer Will become connected with the headiof the back cheek, which prevents the rebound of the hammer. As the key descends, the spring N presses the detacher [i and its stern L upward under the benin V`er-tiutt et M, by which the hammer is slightly raised. The jack will connect again with the hammer-butt, so that the blow may ie repeated with a smallpart only of the motion of the lrey. The friction by detaehing the gjack from the hammer-butt has been a great defect in the actions at present in use. By my construction when the key is pressed down the hammer risesto about three-eighths oi an inch from the strings. Then the detacher .l strikes against the barB Without friction, and the jack becomesl detached with a very quick motion, and this adds to the power of the blow.- Itis' thus seen that' the stiffness .common in other actions by det-aching the jack is also here obviated by the elastic de-"l tacher J, and this adds much to the lightness, power, and durability ofthe action. Y

it is important in piano-forte actions to produce by the normal and only small movement of the keys the greatest power te the blow of v thehammencombined with an easy, light, and g elastic touch. To regulate the height of the jacky screw,

9 i :sama-.e

, Shrinking und swelling. of the wood, and the object of fhis mede f' nffnehing is fo remedy that difficulty. Another inode of attaching il. is represented at U :rnd V, :nid it is apparent that any Shri liking or swelling of the wood will be compensited and :my looseness prevented. The upright piece of Wood XV in the hingebutt is for the same purpose :is the piece S in the lever l". A spiral spring, T, attached to the jack I :ind the defnelier J, :is Shown in the drawing, will be found more convenenfl in .fictions for smell pimms than the sp1-i115 .\`,at taehed to' the lever l".

XVhat I elnini as my invention, :ind desire to secure by Letters ,l..itent is-n l. The combination of the vibrnfi n g defziehe1' J' und its adjustable Stein L with the inek I, substnntinlly as herein shown und described, 2. 'lhe form and peculiar eoustruefion of the lniunner-butt l), of thejnelc I, und of the defneheri, substantially :is described.

3. The mode ofultuchnf,r the levers, bingebutts, &e., substantially :is dilseribed, or ifs equivalent, for the purpose of preventing looseness und the efl'eefs of shrinking und swelling.

(l. lfl'CXllY llll'iSlL-'Vll Witnesses:

Ulrlnlyias l). Anni-1N, JNO. linien. 

